Motor.



Patented July l6, I901. W. A. JONES.

M 0 T 0 R.

( Application filed Oct. 22, 1900.)

2 Shasta-Sheet I.

(No Model.)

I has M MM a Z I! J2 0% i wx IN VENTOH A TTORIVE Y5 Patented July 16,l90l.

W. A. JONES.

MOTOR.

J J I I PATET 11 error.

WVILLIAM ANTHONY JONES, OF WEST BRIGHTON, NElV YORK.

MOTOR.

SEEGIFIGATION forming part of Letters Patent N0. 678,570, dated July 16,1901.

Application filed October 22, 1900. Serial No. 33,862. (No model.)

- To all whom it may concern:

Be it known that 1, WILLIAM ANTHONY JONES, a citizen of the UnitedStates, and a resident of est Brighton, Staten Island, in the county ofRichmond and State of New York, (post-office address Lathrop and Dickieavenues,) have invented certain new and useful Improvements in Motorsand Compressore, of which the following is a specification.

This invention relates to rotary motors adapted to be driven by elasticfluids and to a particular improvement in such motors whereby thedriving fluid operates expansively through a series of successivechambers. The improvement therefore relates specifically to that sort ofrotary motors wherein the rotary pistons are in the form of intermeshingscrews.

The main object of the invention is to so construct the motor that steamor other elastic fluid may be admitted thereto at a high pressure andafter its successive expansion exhaust therefrom ata low pressure andyield a nearly-uniform turning moment available as motive power. thismeans the motor will have a great advantage over most of the formerrotary motors, since thesurfaces which come in contact with theexpanding fluid will remain at nearly-constant temperature,therebyavoiding the loss in efficiency in said former motors due to alternatelyheating and cooling such surfaces. This improved construction also makesit possible to expand the fluid advantageously through a much greaterrange of pressure than is possible with most former motors and enablesthe motor to be run economicallyatlow speeds.

Another object of the invention is to reduce to the minimum the loss dueto any leakage of the fluid from one isolated space between the threadsof the screw to the next one. This is accomplished partly by theconstruction of the periphery of the screws and their casing and partlyfrom the fact that what fluid should'so escape will be available forwork in the isolated space to which it has escaped.

Another object of the invention is to so design the motor that it may beeasily and accurately constructed and also in a manner such that onlyradial action of the elastic fluid in the isolated spaces becomeseffective, thereby avoiding end thrust on the screws and greatlyaugmenting the ease of operation and maintenance. To the accomplishmentof these objects the invention consists in the construction, formation,and arrangement of parts hereinafter fully described and'claimed.

. In the accompanying drawings, which form a part of the specification,Figure 1 is a longitudinal vertical section through the motorcasing,taken in a broken plane indicated by the line 1 1, Fig. 3, which passesthrough the valve-chest and valve and through the axis of one of thescrews, a part of said screw being left in elevation. Fig. 2 is ahorizontal section through the motor, taken in the plane indicated bythe line 2 2, Fig. 3, the screw being shown partly in plan. Fig. 3 is avertical transverse section taken in the broken plane indicated by theline 3 3, Fig. Fig. 4 is a view similar to that in Fig. 2, showing amodification in the form of the threads of the screws. Fig. 5 is adiagrammatic illustration of the action of the elastic fluid in anisolated space, whereby rotary motion is im parted to the screws. Fig. 6is a transverse section through an isolated space to illustrate theeflect of the expansive force of the clastic fluid therein.

The principal elements of the motor are the right-hand screw 7 and theleft-hand screw 8,

which are mounted on shafts 9 and 10, re-

spectively, and the casing 11. In said cas ing are formed twocylindrical chambers intersecting each other laterally andlongitudinally and in which said screws are mounted. In each of thesescrews the space between the threads deepens gradually from one endtofthe screw to the other, so that the bottom of said space is a conicalsurface. The perimeter of each screw, however, is a cylinder. Each screwmay therefore be readily and accurately turned up in a lathe-that is,with respect to the top of its threadsand the chamber for each screw maybe readily and accurately bored out, so as to make a close fit with thetop of said threads. The screws intermesh, as shown, so that the top ofthe thread of one engages the bottom of the space between the threads ofthe other. This causes the shafts 9 and 10 to converge, as shown. Saidshafts are geared together preferably near their converging ends bygears 12 and 13, which are for the sake of cleanliness and ease oflubrication located within the casing 11, as indicated. The sides of thethread of each screw are concave and are such surfaces as would beformed by the helical corner of the intermeshing thread of the otherscrew, so that as the screws revolve together each of said corners is incontact with the side of the intermeshingth read of the coacting screw,thereby forming a seal throughout the overlap of the threads, which,together with the closelyfitting casing, cuts off from communicationwith each other the successive spaces between the threads that areformed by the intermeshing of the screws. By means of the cylindricalform of the outside of the screws this generating-helix is of the sameshape throughout the length of the screws. This enables the sides ofthreads also to be finished in a lathe. These successive spaces are ofsnaillike form, as seen at 14 in Fig. 5, each increasing in depth fromone end to the other. The successive isolated spaces also increase involume from one end of the screw to the other, so that the elastic fluidtaken in at one point along the length of the screw gradually expands asit moves therefrom to the exitport of the motor, which is indicated at15, Fig. 1.

The elastic fluid may be admitted to the isolated spaces at any desiredpoints along the length of the screws. This may be accomplished andcontrolled by means of a slide-valve, substantially as shown in Fig. 1at 16. A chest 17 for this valve may be located upon the casing 11, towhich an inletport is provided at 13 and an exhaust-port at 1'9. Thedriving fluid is admitted from the chest 17 into the isolated spaces ofthe screw 7 through ports 20 and to those of the screw 8 through theports 21. The valve is in the cut-off position in Fig. 1, and by movingit in the direction of the arrow 22 the exhaustport 15 is disclosed andone or more of the ports 20, as desired. When the first one of the ports20 is opened, the fluid is admitted to an annular groove about eachscrew-piston, as indicated at 23. From this groove the space betweenthreads has its origin. A larger volume of driving fluid may be admittedto the screws by disclosing more of the ports 20. These ports are madenarrower than the width of the tops of the screwthreads in order thatthose ports still covered by the valve shall not connect the isolatedspaces. Obviously the groove 23 may be formed in part or wholly in thecasing, or it may be omitted. Each screw is also provided with suitablepacking to prevent the escape of the driving fluid. Such packing may bein the form of rings, as indicated at 24.

The casing for the screws and the steamchest is preferably made from asingle casting or forging, the chambers for the screwpistons and thevalve being bored therein and the outer bearings therefor being formedin the heads 25, 26, and 27, respectively,

threads at the sides of the space.

which may be bolted or otherwise suitably held in place in the ends ofsaid chambers.

To counterbalance the end thrust of the screws due to the pressure ofthe fluid on the end of the screws in the spaces 28, into which itescapes on leaving the last isolated chambers, said space is connectedby passage 29 with spaces 30 at the opposite ends of screws 7 and 8. themotor is reversed. I

In Fig. 3 the relation of the screws to one another is shown, also therelative location of the valve-chest and the series of ports 20 and 21,and the direction of rotation of the screws is indicated by the arrows31 and 32.

This is especially important when 7 In Fig. 5 the diagram of forceseffective in producing rotation of the screws is shown, and referencethereto will make more clear the eflect of an elastic fluid in themotor. This figure represents a section of the screw 7 on a surfacegenerated by a line perpendicular to the axis of said screw and movingthrough the middle line of the bottom of the isolated space 14 and asection of screw 8 on a similar surface generated by a lineperpendicular to the axis of said screw and moving through the middleline of the top of the thread 33 of screw 8, which meshes between theconvolution of the thread of screw 7 that forms the lateral walls of theisolated space 14. The ends 34 and 35 of said space are formed by thesaid thread The outer surface of this space 14 is the cylindrical wallof the casing 11, and the inner helical surface is the bottom of thechannel between the The View in this figure is taken looking along theaxis of screw 7. The action of the elastic fluid in this isolated spaceis typical of its action in all the other spaces. The action thereoftending to cause the screw to revolve is indicated by the arrows P,which represent pressure against the wall of the case. The arrows Nrepresent the pressure against the bottom of the isolated space, and thearrows T represent the resultant of these two pressures finally reactingagainst the top of the thread of the screw 8. The lines of direction ofthe pressure N pass to the side of the axis of the screw 7, showing thatthis pressure creates a moment tending to revolve the screw 7. Thismoment is equal to the sum of the forces N multiplied by their effectivelever-arm and is equal to the sum of the forces T multiplied by the meanradius of the spiral forming the bottom of the isolated space. Theresultant action of these forces is also graphically indicated by thelineT, which represents a pressure acting and reacting upon a portion ofthe end wall 35 of the space 14 and the helical surface forming thebottom of said space. The remaining portion of the wall 35 equals thewall 34, so that the action and reaction on these surfaces balance oneanother. The turning of the screw then may be said to result from theaction of the forces T on that portion of the surface 35 which isopposed to the said helical surface. The forces of the expanding fluidacting in other directions also counterbalance each other betweenrelatively-fixed walls, as indicated in Fig. 6 at X. These are theforces which tend to produce end thrust of the screws; but since theyact parallel to the easing 11 they can produce no end thrust. Thiscondition is brought about by the fact that the casing and the perimeterof the screws are cylindrical.

From the foregoing it will be seen that of the forces exerted by theelastic fluid as it gradually passes along the screw intosuccessivelyformed isolated spaces none are made effective save thosetending to revolve the screws.

In the form of motor above described both screwpistons share equally inthe work. The work may, however, be thrown mainly upon one of them byvarying the form of the threads, as shown in Fig. 4. Therein the spacesbetween the threads of screw 7' and the threads of screw 8uniformlyincrease in width from the inlet-port to the exhaust-port, thedistance from center to center of successive threads of each screw beingconstant in each case. In this instance the isolated spaces of screw 7receive the greater volume of steam, and said screw therefore takes thebrunt of the work, the other screw serving for little more than tointerpose its intermeshing threads for abutments or end walls to theisolated spaces of screws 7 Because of this and because it is from theshaft of screw 7 that the power is taken the power transmitted by thegears, and consequently the wear upon them and the journals, islessened. This mode of construction also facilitates the accuratefitting of one screw to the other, since in turning screw 7 into meshwith screw 8 the narrower convolutions of screw 7 will first enter thewider spaces between the threads of the screw 8, and should they fail tomesh perfectly the screw 7"may be readily withdrawn and the defectremedied.

The motor is operated and controlled by the movement of the valve 16 toadmit more or less steam or other elastic fluid into the ports 20 and21. It maybe reversed by admitting the steam at port 15 through thehollow valve from the inlet 18 and disclosing the ports 20 and 21, so asto provide an outlet for the steam (through port 19) before thecompression thereof offsets the power applied thereby to the screws.

Though the apparatus as set forth above is designed primarily foroperation as a motor, it is obvious that by applying power to the shaft9 it may be run as a compressor, the fluid to be compressed beingadmitted at port 15 and discharged at that one of the ports 20 or 21 atwhich it reaches the desired degree of compression. Operated as acompressor it has advantages over former compressors in that it may bedirectly connected to an electric motor and run at a high speed, also inthat it avoids all the loss due to clearancespace and lifting-valves,that it requires no fly-wheel, and that the progress of the elasticfluid through all passages is sensibly uniform.

This apparatus, which, as already stated, may serve in the capacity of amotor or a compressor, may be varied in proportion and in form of partsin ways other than those already cited without departing from the spiritof my invention.

I claim as my invention- 1. In a rotary motor or compressor, a casin ghaving suitable inlet and exhaust ports for an elastic fluid and havingtwo cylindrical chambers intersecting each other laterally andlongitudinally, in combination with a right-hand screw in one of saidchambers,and a left-hand screw in the other one of said chambers, eachof said screws having a cylindrical perimeter fitting the side walls ofits chamber and having the bottom of the space between the convolutionsof its thread on the surface of a cone, the sides of said thread beingso formed that the thread of one screw will intermesh with that of theother screw and closely engage the same throughout the entire distanceof the overlap and also closely engage the bottom of the space betweenthe threads, thereby forming an effective seal be tween the isolatedspaces of each screw.

2. I In a rotary motor or compressor, a casing having two cylindricalchambers intersecting each other laterally and longitudinally, incombination with a right-hand screwin one of said chambers, a left-handscrew in the other one of said chambers, each of said screws having acylindrical perimeter fitting the side walls ofits chamber and havingthe bottom of the space between the convolutions of its thread on thesurface of a cone, a valve chamber on said casing having a series ofinlet-ports communicating with the isolated spaces of the screws and anexhaust-port, and a valve for controlling said ports, substantially asset forth.

3. In a rotary motor or compressor, acasing having suitable inlet andexhaust ports for an elastic fluid and having two intersectingcylindrical chambers in combination with a right-hand screwin one ofsaid chambers, and a left-hand screw in the other one of said chambers,each of said screws having a cylindrical perimeter fitting the sidewalls of its chamber and having the bottom of the space between theconvolutions of its thread on the surface of a cone, the thread of onescrew intermeshin g with that of the other and extending to said conicalsurface and each havingits side walls concaved, for the purpose setforth.

4:. In a rotary motor or compressor, a casing having suitable inlet andexhaust ports for an elastic fluid and having two intersectingcylindrical chambers in combination with a right-hand screwin one ofsaid chambers, and a left-hand screw in the other one of said chambers,each of said screws having a cylindrical IIO perimeter fitting the sidewalls of its chamber and having the bottom of the space between theconvolutions of its thread on the surface of acone, each screwintermeshing with the other and having an annular space about it at theinlet-ports, from which the space between the threads of the screw hasits beginning.

5. In a rotary motor or compressor, a casing having suitable inlet andexhaust ports for an elastic fluid and having two intersectingcylindrical chambers in combination with a right-hand screw in one ofsaid chambers, and a left-hand screw in the other one of said chambers,each of said screws having a cylindrical perimeter fitting the sidewalls of its chamber and having the bottom of the space between theconvolutions of its thread on the surface of a cone, each screwintermeshing with the other and having a space between the casing andthe end thereof opposite the exhaust-port which communicates with thespace at the exhaust-port end of the motor, as and for the purpose setforth.

6. In a rotary motor or compressor a casing having suitable inlet andexhaust ports for an elastic fluid and having two intersectingcylindrical chambers, in combination with a right-hand screw in one ofsaid chambers, and a left-hand screw in the other one of said chambers,each of said screws having acy- 7. In a rotary motor or compressor acasing having suitable inlet and exhaust ports for an elastic fluid andhaving two intersecting cylindrical chambers, in combination with aright-hand screw in one of said chambers, and a left-hand screw in theother one of said chambers, each of said screws having a cylindricalperimeter fitting the side Walls of its chamber and having the bottom ofthe space between the convolutions of its thread on the surface ofacone, the screws intermeshing and the sides of the threads of eachscrew being a surface such as would be generated by the helix formingthe corner of the intermeshing thread of the other screw, so that as thescrews revolve there is a line of contact between the sides of thethread of each screw and the corresponding helical corner of itsengaging screw, thus forming a seal between the isolated spaces of eachscrew.

8. In a rotary motor or compressor, acasing having two intersectingcylindrical chambers in combination with a right-hand screw in one ofsaid cham bers,aleft-hand screw in the other one of said chambers, eachof said screws having a cylindrical perimeter fitting the side walls ofits chamber and having the bottom of the space between the convolutionsof its thread on the surface of a cone, a valve-chamber on said casinghaving a series of ports communicating with the spaces between thethreads and at the ends of the screws and a valve in said chamber forcontrolling said ports and providing for the'admission and discharge ofthe elastic fluid to effect an advance or reverse movement of thescrews.

9. In a rotary motor or compressor, a casing having suitable inlet andexhaust ports for an elastic fluid and having two intersectingcylindrical chambers in combination with a right-hand screw in one ofsaid chambers,-

and a left-hand screw in the otherone of said chambers, each of saidscrews having a cylindrical perimeter fitting the side walls of itschamber and having the bottom of the space between the convolutions ofits thread on the surface of a cone, each of said spaces beginning at apoint between the ends of its respective screw and terminating at oneend thereof,and the screws intermeshing one with the other.

Signed at New York, in the county of New York 'and State of New York,this 17th day of. October, A. D. 1900.

WILLIAM ANTHONY JONES.

Witnesses:

DELBERT H. DECKER, ETHEL L. LAWLER.

